SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '056974f31e61fa915f68198a32702b8caceeb07c528b4ac1cfcac7b53e31c3d0' 
  AND token = 'X4YBrGKCiZnJaDZm8Yr/ajzuxy8BsL0KZbfJGExcELY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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