SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f45c4ad906813d977423a236040cd1068b5b07bfee42cb6167d632b14f5af197' 
  AND token = 'bDin0g3CJRuOsfsPJ5WnC12mwlFfgVOfB9xOHv1+DNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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