SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e8bb33699b7d492e4a35a5360428679885881be8c38475a0a84395d1f628c4f2' 
  AND token = 'Irzkb7kW4TaA+mGLn6A9fPJ9esWskk9w139HXhVoFRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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