SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08493dcb52f85adb318c13c84e39471f54b972d2828cba0da4b833b3770810a' 
  AND token = 'e9ukkby0dUYmc88KL2Rlxp0v4LhK2vRQ1LhFFttgmNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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