SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1331137f9c1d920a8e2908f6396451929cdbfbff2c0582f68d30a158eb43f2e7' 
  AND token = 'Vg/Jo/qSmDdzyB/qI0D3pNaQlwNKIVArs8pJxUmRzco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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