SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4e9f0fb7cd9370cb787ffd0489f367888aa429fa54e5a99c0bd4c95b0ed9d1c' 
  AND token = 'cXCM1gpMobxZClWJA+PHHG6W251gRyszMhRNy5KtV/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00095

JSON explain

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