SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87dc94ab4e96568b13afde3ad229d90f5e2a091e85db391089294562d6ab7061' 
  AND token = 'ywMj1GeUpx9PDowFq8lHsO2D/1AfQorJtj4vFwMvX/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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