SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c87c6f08b9fc108411ab0bd3ac0355d5bb32f7d8a756af9656f34a48e556973e' 
  AND token = '+CXq6V6awpIT2nza9zDYJok1fY5KH/0qsHGQ1jyZorM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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