SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91fef369d40f66024923aa4128373a7aa4d93fcca7c802c02c85874ef30c0505' 
  AND token = 'fsoNIb71Ak/Z2RrJbL3nwkjQ5NXmTfwLSvQgYQ7uj6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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