SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd57dd6312ab644f9483e007321f322cd2aeddbf4da5dd01a1e0894c383dfa602' 
  AND token = 'bBEz1qBOZ9lraExJvacFYs4EuIXbGUQLl9A0mbfTks0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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