SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abb24e704947a495da4b1d998f67136cc9d81bcb6df3ae3276cb1325f7ec31c7' 
  AND token = 'n4GPl24zuRJYrgiNpDC92so2IsOHvz/QORu3WTXjrDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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