SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5086b5f52daecf229ea84d12dab6cd79c4ceafb0c65f1800b7f6f1e4d7ec831' 
  AND token = 'NOxndVv2KplvC110H41WJUwngDj0sXRWCYVTC5mijJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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