SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c4af7895bbb9ea90308fa42113f2b16868aced216c62b8165a259b895809c4f' 
  AND token = 'OGM9JDxMl/CMTpuhYHNZzz1Q+WlqzGFKWAXUrhKpgUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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