SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e48ed56fae47d7720df985fbb8b87f0997692a46b53dd206fdca47907ad0efe' 
  AND token = 'Cay01CHow2wooBBS+NPuQR44Hhc4xSHdbMSdwESaTtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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