SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40378b7da24dd9cf192d8005f3ea257a1f1a65f248e01c1f706b35c37d8bfbb0' 
  AND token = 'WfnZbsVUV2dnGYQ4C2TPo+dWoQYqf1Zrapx+AxW4WEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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