SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e2b4512ced44b8ed78ba16e983e39c5cf61e0e4573eeb48b5754888b52ec197' 
  AND token = 'PiCcPLMDJ0q7rodilZaUHDNKwdb0ibsrl0dxj2eoNPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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