SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f5dc351693e6ab1561ff9c9bc3f7e8e788bf7f32c6f91cacf8718206b0c6d7d' 
  AND token = 'FFjh5vmj9W6dq7yT/vzv0UhUboR+rjU4YQTMzbpmThs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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