SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522e1b92c35ac07cc05c9b1278fcb8b4c8bd9bd5c8069a7f349809d17ade6cfe' 
  AND token = 'GONpztVDrjXZTB3Lwr1d2N/PqjZbh5UHjQDBKDHxkJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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