SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff6401ad48c3725c4883248d45d056f4857c7bbafca08f165116d916e2657fad' 
  AND token = 'G5hQloPsV2cvVNDd0KKkxDE5OH1zMn1+ThhfPdg1vKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}