SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e30f94a229b9bb7f0f7a2581d4943da77471aa4ac2ab18db5afef705da96459' 
  AND token = '5qRJsc6tUJEKXopNeLHopcI9fdJFsOAgRtPrjUEFLdY=' 
  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"
    }
  }
}