SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b889691519e0cef856685576ef0f24573d4ff27a1764725e35197ce958da1700' 
  AND token = 'Bwwi96oMpWq3RJdZAjMpkvafDpujCVAxJiG2gT7LmyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00109

JSON explain

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