SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65f042df492ff182a2ae70a9373160c8e1de7a9b12124f9a5f02dd2aa09fe473' 
  AND token = 'mixgK27+GC6etJvVFCpFftyB/c4VDep+luQ5FsdCfIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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