SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da272e1ce52956d3305b6c915ab38302d452601c50f65733fe35f4037179390d' 
  AND token = '1Iw0Otyze3he9EZKMFGlYZ+Lbd685gdQYh+tHKmRSvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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