SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2eae08d86845cbe91090db9bd3b85e95caeb9e12bf7ae67b20a73360cf8873e' 
  AND token = 'VNHxjVElWgIBmWd0XRSu2tEz3lSMe2+AzaKvNScn87E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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