SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d2e07ccb81fbb5f816dbf338342dde8807ce0c71c52b73436ed64395aed9443' 
  AND token = 'ND6jTC51Ai/YkpUJ8LoqQxwHV9PDjQYK06osUDJvGXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}