SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee7fde787e555574d1f0bf2764a7fb19d7b472c7ddc81facabe4ef2d5a49a589' 
  AND token = 'jO613FepwNJrJeS+oPWFPrPdD34eSxgtp/Zjsu9/bkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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