SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4606d64cf5c8ca670bcb86151fb20a2178998c1fbd3094c52a0b5d6fb55dda0' 
  AND token = 'a8aR056fmat0UIvFU/nSYOkS6bWmoyZyNRQyg/AHLpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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