SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4d945f67d42eba9b48b298bed8f994d5c2e66c4f4e07e51ce9a9068d6713106' 
  AND token = 'dJGrLopL7wPFf+xFnPGD3yfymulxJCZa05HB/cpBhVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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