SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c58e0003f34ff736852886547ba66406e571f73f0ba226763d26691e783e06' 
  AND token = 'A+uHNTT1Dw/a4tCghedGjY0EFxYmvpJwApkUjGGNvug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}