SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '244afa0d89a2dee5b12eba430febccf2991169547d22c29eb4db01c5c35b8b59' 
  AND token = 'LUwtIsMj6F7jlUgO9l8hZSCUDV6oJytvzm6YQqBFdmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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