SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c914f45aa9fd389cc14e310cfa7646cdfcdb74de3e4e22f8064d628d0fb5c608' 
  AND token = 'hX5rm4Vf2pLVQTRfVla2ZaWCMFnXgsMBpAatpdyo/4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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