SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '232ad46b9165c2e33dbfa59d57b7fa3a65b3e60b4c057b5769534b69a43961a9' 
  AND token = 'mqKMxGMkJbzlXESAgClBNPwqQwOWro4qlwd+9tyOvT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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