SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6ba0d0ccf5af531e8418ee36505aa02fe3d82159f253f224a6e3c5f4be73e9' 
  AND token = '0MzZgOdusKj4POups6hBzpZvd2W+zJkvy5ooYPqMBc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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