SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1a1949649dabcfd36c98f956706381761e5823522463c4a28366903a1fe79ac' 
  AND token = 'IvpAx1Z2PpsiMGikBCW4bPGe9N7wcp4iQBSeSH0yrk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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