SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9dddccc597e1238979ccfb7b86b64a42e1f023448f59e768c82fdcd10414cfa' 
  AND token = 'xjSlCP020fwXTLw6+Q/+JdDLBc/7fGR6pmrcDVah2LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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