SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e731dd2b33f05896f6cf03328a3514a0006f18aae2a1f6386480651e9ea7ffce' 
  AND token = 'kzSDEpomWEzQdkMxG1X71gdOd+iXOEmok8Bm91qiFtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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