SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd41dab1a2530ce4911d5ad1eb6e27488a72d7b68926997ba8952359c2224fd6e' 
  AND token = '0mWH4toFt2Oz0JpiSKGfxn/9WtHNfAjyr9SFnZz8zaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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