SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f342dc02caf07cd8e7aedb131cec58425d8b6039ff87306f6183541adb4a52' 
  AND token = '+He890SQ+2EYQ8qs5yRrF8L+yLBMB6uVj2pdPjV04TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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