SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb5c4d100a1af73182fc0fa49065c66239aba86d50985aac73ac10418abaed31' 
  AND token = 'lMVrwWzoQvZRK7G6IIiLNGit6xY2zMAo31FVc11xZ2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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