SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b923334d02e6c1562ac7084edf4555f7351adf1e10e0460b75c60a7fa869988' 
  AND token = 'XgFPzWwTyoW4YQM9JrC9krhlY3vQ67Cp/CuMP8DczUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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