SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba133dfe6fe312a4bb883d84a0be5a8af73b9cc06f3163ce221e45e94054600a' 
  AND token = '83KYegV4JFmGzcDA7pNdKWJtwlMpVDEamKswtol6iGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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