SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75e229fced830a439658fd98f3984a9e9e2c928d52a36553943549f8368f3797' 
  AND token = 'BdJY2T6/lnkWpWnmyO4sD/JdIBZLN1qw6bO5Vgd78w4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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