SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4acb54d4df574ed7a2c64114b27336a729d67523bad30d2114b63f2ee541ca78' 
  AND token = 'ZjLCi8Zk5QWTFgwDAq3CUhIcVGGAGw0uuXsjBNaNbWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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