SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f8ea33c41345d6f66219457247a2f865a99facdf47dda265fd1c9ab9c3b2431' 
  AND token = 'qwpNo3/yDw7OYIj43bRU+5SK2kmlXmFtQG2bjzpmmPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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