SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2711129d84036bdaf98516af3ff97db05b3ab2370eea7373e26f3200368c8953' 
  AND token = 'DFARLhKkkNheYdnh//GE6pnFyaki2sErq/+6j2YREgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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