SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd74939e0d6d83d0c7a6b19ddbc051b8e3f38af8bf58cc773e185da81f6970cc4' 
  AND token = 'bWknXpUPQyEUaR2qG4zblWV55n20LbDbBlHynVaYpnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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