SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '379dc7529f08f7df81f0b7f178f3ba754d5d45a8735533ab00ccab72f238f09d' 
  AND token = '3+h/jZCcoUy0oG6YG3RXSmfzJNCBMH0W6AFocqewBJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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