SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7e780ad1322b93dd138361c0a724673742ddd3579023eadf26ba72ab036131b7' 
  AND token = 'tPb2QiBrwg/5hBGL7U+aMHj7/jh8ZgzA5uR9lm+nnjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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