SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '726ebaa41c9efafd9b060e19cc4598a27343612162fe1f1eef814eb082603dc8' 
  AND token = 'oLvRX/nMR+SrEk0YQ8x67c1CbhaIXP/T10hlUUsw6gc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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