SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '441bf288a322ab224f2b47116f043480e1e58a18c2ae41bfca4cc397815b53db' 
  AND token = 'TjZKuhg7GYOeeNv5UG+xh46S6rNKRutyj3qc/BG8JVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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