SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a64ac1b082fb73b05a5f6b1abaca4bded78b25f41bdac973fcb481555881a7b' 
  AND token = '9qGbyavwe7aJATJvMIJMaEHrZWsUOz7Nw/G+Qh4Ad3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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