SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2291b8a4ed75d47e7c621ce94e72cb4f4958ccbaac2646307db2fc404661b29' 
  AND token = 'Aj8VhUtHANVPjHxlQzccZAwrqGOqZzLhtn2pM/xA5uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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