SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09afc311a59110360bf2f5dd722e143361fd489c6bb1d846a91d5d4b23a0dc0e' 
  AND token = 'QhL9hkaqbQ+VB9Qjkmn1lZh/Caq96TcB+HlOZfV/Kdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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