SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b94caa98bcaa2a0a1074dfe564f9b53b9419e7394c41c20c3bbad563998c69ef' 
  AND token = '9C0n5jWfHrqpF2vlzY2jhkcwKGQC2AsKomkLIoZGYw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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