SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea1ff5a3776278208897ae1905e70db292f12fed5138829bd68208c25aa7b221' 
  AND token = 'gCKzkHlVn6Mw0wQhBpMDMs5ogWhmugOLbcZ7+HY+38g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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