SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a27eda034021a53f852952591ac67413d61916a39d801ee9ef3494427d04421b' 
  AND token = 'WCqGACETo9Vv160jAlYXJEFZ/E4HcPJC7wP8vM3m4Po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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