SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8a8f33cf8b822f018c3a9dc318e05129d81db181a36abea09aaa348f294f6e9' 
  AND token = 'oB+7iu7G1g5auudOQi4Y2l715zM3uQrQJqq7AYyquAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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