SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91de5469a0865ebe4a37abbfd9bf0c631caff674e4db6b1110ab153c3d0031c1' 
  AND token = 'r4fqvPVFtsmYYGDCbPiXo5O5zCx4CbfZPIGb1jzim+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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