SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dedb7a640ecf6a5ee8e57ce9eeb533d2eab305e5303c89632f232f50e37fe84' 
  AND token = 'dVwdmChuiM1qJQXz6UZKoI4qIY+Vb/vGwlgJc/6h/iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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