SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8620806640ae95630430f6ee0fbbe2413835f9efc1eba6a319b25923a85ef63e' 
  AND token = 'yFdjjZ0tPtXU6BaUfyFZf3WUu2Y0XzJLEabquA3fF/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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